As engines accumulate mileage, carbon deposits may build up over time. Such carbon deposits may accumulate on top of one or more pistons in one or more engine cylinders, and/or on the intake and exhaust valves of the engine cylinders. Such carbon buildup may be the result of frequent drive cycles that are short in nature, regular use of low grade fuel, improper air/fuel ratio during vehicle operation, etc. In the event of such carbon buildup, the engine may run rough and may be sluggish to respond. Furthermore, such carbon buildup may degrade fuel economy, increase tailpipe emissions, and may cause knock issues while the engine is combusting air and fuel.
To address these issues, engine additives are often utilized, which may serve to clean engine cylinders of such carbon deposits. However, such additives may be introduced into an intake manifold of the engine, which may thus require intrusive actions such as disconnecting a vacuum line in the engine, and introducing the additive fluid to the engine via the vacuum line. In other words, such a solution may not be desirable to a vehicle operator, as the vehicle may need to be serviced to conduct such an operation. Still further, such additives are costly, and many vehicle operators may not be aware that such additives even exist or that they may be useful for particular aspects of vehicle operation. Still further, there may be circumstances in the future where vehicles are autonomously driven (e.g. autonomous vehicles), and as such, there may not be a driver present to notice engine sluggishness due to carbon buildup. In such cases, fuel economy may become degraded, which may lead to undesired emissions being released to atmosphere.
The inventors herein have recognized these issues, and have developed systems and methods to at least partially address them. In one example, a method comprises, in response to an indication of degradation in one or more cylinders of an engine of a vehicle, reducing a carbon buildup associated with the one or more cylinders by injecting a diesel exhaust fluid into an intake manifold of the engine, and drawing the diesel exhaust fluid into the engine while the engine is combusting air and fuel. In this way, the carbon buildup may be reduced in an onboard, and on-demand fashion.
In one example of the method, the diesel exhaust fluid is stored in a tank positioned in a diesel exhaust fluid system, where a first diesel exhaust fluid line is configured to selectively route the diesel exhaust fluid to an exhaust passage, and where a second diesel exhaust fluid line is configured to selectively route the diesel exhaust fluid to the intake manifold.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.